"Companies expect stronger security than consumers," says Zhu. "Offering a more secure solution to consumers will likely help attract business customers to the service."

While basic encryption is not technically difficult, several pitfalls lay in waiting for the search giant.

What would happen, Zhu wonders, if there's a lawsuit and the consumer claims they forgot the password needed to decrypt potentially relevant data? Or if a consumer stores data owned by their employer in the cloud and the employer finds out about it? Or if a person dies and their property, including their data, is supposed to pass to their heirs?

"It is unlikely that such issues will be addressed quickly, especially with a free service," says Zhu.

Security pros have long known that there is little privacy protection proffered in broadly distributed free consumer services like Drive and SkyDrive.

"Ironically it's taken the NSA PRISM scandal to raise the issue of privacy protection to the point where Google is implementing storage encryption, but this is just one in a series of steps," Zhu says. "Consumers have a cavalier, lackadaisical attitude towards security. Improvements in privacy protections mostly happen as a knee-jerk reaction to highly publicized negative events."